Method and apparatus for cleaning liquid seals of vacuum chambers



Aug. 10, 1926. 1,595,476

- (J.JMIN1TDN METHOD AND APPARATUS FOR CLEANING LIQUID SEALS OF VACUUMCHAMBERS Original Filed May 25, 1920 2 Sheets-Sheet 1 5% WWW ATTORNEYAug. 10 1926.

. 1,595,476 0. MINTON METHOD AND APPARATUS FOR CLEANING LIQUID SEALS 0FVACUUM CHAMBERS Original Filed May 25 1920 2 Sheets-Sheet 2 BY 4 (22M vATTORNEY Patented Aug. 10, 1926.

UNITED STATES.

PATENT OFFICE.

OGDEN MINTON, OF GREENWICH, CONNECTICUT.

METHOD AND APPARATUS FOR CLEANING LIQUID SEALS OF VACUUM CHAMBERS.

Application filed May 25, 1920, Serial-No. 384,211. Renewed February 17,1926.

which is more or less removed by the liquid seal and forms a scum whichwill float upon the surface of the liquid seal. Other and cleanerportions of the same or another web will take up this scum and be marredby it. My invention is to remove this foreign matter from the liquidseal.

My invention further relates to cleaning the liquid,seal withoutbreakingthe vacuum in the chamber. My invention'further relates to permitting aportion of the liquid seal to escape from the sealing chamber, becleaned and returned to the sealing chamber without breaking the vacuumin the chamber.

My invention further relates to certain methods, apparatus,combinations, and details Which will be more fully hereinafter describedand set forth in the claims.

In the accompanying drawings the same reference numerals refer tosimilar parts in the several figures.

Fig. 1 is a vertical section of one form of apparatus, which may be usedto carry out my improved method, shown connected to one form of vacuumdrying chamber;

Fig. 2 is a vertical section of one form of my apparatus shown connectedto a diflerent form of vacuum drying chamber;

Fig. 3 is a vertical section of two of my cleaning apparatus connectedto different liquid seals of a vacuum drying chamber;

Fig. 41 is a vertical section, similar to Fig. 3, except that the partsare so coupled together that one cleaning chamber and pump is usedinstead of the two separate units shown in Fig. 3.

In passing a wet web 1 of paper, or fabric or other'sheet material overthe guide roll 2 and through the liquid sealing medium 3 mounted in thesealing chamber 4 under the guide roll 5, and thence into the vacuumdrying chamber 6 it is found that the liquid sealing medium 3 willoften, in parts of the .111 of the web 1, become foul with foreignmatter, such as dirt, oil, fibers, and other material which'will be moreor less removed.

from the web 1 by the liquid sealing medium 3. This foreign matter formsa scum which floats upon the surface of the seal 3. A portion of the runof paper, cloth, or other material, which is to be dried in the vacuumchamber 6, may be comparatively dirty and that portion of the foreignmatter which is removed from the web will float upon the liquid seal andform a scum. Other and cleaner portions of the same or another web willtake up all, or a large portion, of this scum, but in doing so the webof course will be injured or marred.

By my invention. I provide the sealing chamber 4 with a weir or dam 7and with a well 8. This well is connected by means of the pipe 9 with acleaning chamber 10. Also connected to the cleaning chamber is a pump 11with its pipe 12 leading back to the sealing chamber 4. In practice Iemploy a little more liquid sealing medium 3 than is necessary to fillthe sealing chamber 4 up to the weir or dam 7. This scum of foreignmatter floats on the surface of the v suitable means, such; as byremoving the plug 13 by loosening the bolts 14, 14. During the cleaningoperation the valve 151 may be used to close the entrance to thecleaning chamber 10.

Different sealing mediums 3 may be used which will not injure or mar theweb 1 and which have no affinity for, or deleterious effect, .upon theweb. I may for example use mercury, amalgam, or any other sumlar liquidhaving the characteristics above specified. When mercury or similarmaterial is employed the dirt, oil, fibers oxide of mercury, if any, andall other forelgn matter will form the scum which will flow over theweir or dam 7 I have shown the cleaning chamberlO equipped to cleanmercury, though of course it i t e n e s d that 1t y e equippeddifferently for different forms of liquid sealing mediums which may beused. When mercury or similar material is used I employ a cloth, orchamois skin, or skins 15 stretched across the interior of the cleaningchamber 10, through which the mercury is drawn by the pump 11. The cleanmercury passes into the compartment 16 of the cleanmg chamber and is fedback into the sealing chamber 4 by the pump 11 and pipe 12. Th scum, andother foreign matter, is held in the compartment 17 of the cleaningchamber and is removed from time to time by removing the plug 13. Afterclosing the valve 151 the level of the liquid in the separating orclearing chamber 10 is lowered so as to be below the plug 13. Thispermits the scum and foreign matter to be readily removed withoutwasting any of the sealing liquid.

In Fig. 1 I have shown my method and apparatus in connection with oneliquid seal of a vacuum chamber 6. It of course can be applied to anyform of vacuum chamber using a liquid seal. In Fig. 2 I have shown, byway of example, a vacuum chamber 18 equipped with my invention in whichthe web 1 of paper or similar sheet material is fed over the guide roll2, under the guide roll 3 and thence in contact with the guide cylinder19 partly surrounded by the liquid sealing medium, which is preferably,as previously stated, mercury, amalgam or some similar material. Thisparticular form of vacuum chamber for drying a web of paper or similarsheet material is the subject of my companion application Ser. No.384,212, filed herewith.

In Fig. 3 I have shown a vacuum chamber, such as 6 as in Fig. 1,provided with two sealing chambers 4, 4 each of which is provided with aliquid seal 3. The structure shown in this figure is the same as thatshown in Fig. 1, except that there are two units, one for each separateseal. Instead of two separate and distinct units I may, as in Fig. 4,connect the wells 8,8 of the two sealing chambers 4, 4 by means of thepipe 20,

connecting this pipe directly with one cleaning chamber 10, which inturn is connected by means of the pipe 21, with one pump 22, that pumppumping the clean mercury or amalgam or other similar liquid sealing me-.dium, through the pipe 23 to each of the liquid sealing chambers 4, 4.If desired, the pipe 20 may be provided with valves 24 and 25 and theipe 23 may be provided with valves 26, 2 so that the cleaning may beconfined to either one or both of the sealing chambers 4, 4 asmay befound expedient or convenient.

Having thus described .this invention In 1 connection with illustrativeembodiments thereof, to thedetails of which I do not desire,tohbelimitedywhat is claimed as new Patent is set forth in the appendedclaims.

What I claim is l. The method of cleaning a liquid seal of a vacuumapparatus consisting in automatically removing a portion of said liquidseal without breaking the vacuum, removing the scum or other foreignmatter from that portion of the liquid seal, and automaticallyretllirning said cleaned portions to the liquid sea 2. The method ofcleaning the liquid seal of a vacuum apparatus consisting in using agreater quantity of liquid than necessary to seal the vacuum apparatus,and permitting the surplus liquid to escape from the seal, cleaning saidsurplus liquid, and returning it to the liquid seal.

3. The method of cleaning the liquidseal of a vacuum apparatusconsisting in using a greater quantity of liquid than necessary to sealthe vacuum apparatus, permitting the surplus liquid to flow over a weiror dam, cleaning said surplus liquid, and returning it to the seal.

4. The method of continuously cleaning the liquid of a vacuum apparatusconsisting in using a greater quantity of liquid than necessary to sealthe vacuum apparatus,-and

permitting the surplus liquid to continuously escape from the seal,continuously cleaning said surplus liquid, and, continuously returningit to the liquid seal.

5. The method of continuously cleaning the liquid seal of a vacuumapparatus consisting in using a greater quantity of liquid thannecessary to seal the vacuum apparatus, continuously permitting thesurplus liq uid to flow over a weir or dam, continuously cleaning saidsurplus liquid, and continuously returning it to the seal.

6. The method of cleaning the liquid seal of a vacuum apparatusconsisting in withdrawing some of the liquid of the seal, passingit'through a cleaner, and returning the cleaned liquid to the seal.

7. The method of sealing a vacuum chamber by a liquid and at the sametime keeping the liquid clean so that it will not injure any materialpassing through it into the vacuum chamber to be treated, consisting inwithdrawing some of the liquid of the seal without breaking the vacuumin the vacuum chamber, forcing it through a cleaner and returning thecleaned liquid to the seal.

8. The method of cleaning a liquid seal of mercury or similar materialfor a vacuum chamber, consisting in removing from the mercury foreignmatter which the mercury may accumulate and returning it to the seal.

9. The method of keeping a liquid seal of mercury or similar materialfree from foreign matter consisting in withdrawing portions of saidmercury or similar material, cleaning said portions and returning the11. The method of maintaining a vacuum 1n a vacuum chamber by means of aliquid seal of mercury or similar material -matter, consisting inautomatically withchamber, a liquid seal, and means to clean and keepingthe mercury 01: similar material .free from foreign matter, consistingin withdrawing portions of the mercury or similar material withoutbreaking the vacuum, cleaning it to remove all foreign matter, andreturning the cleaned mercury or similar material without disturbing thevacuum in the vacuum chamber.

' 12. The method of maintaining a vacuum in a vacuum chamber by means ofa liquid seal and keeping the seal free from foreign drawing portions ofthe sealingmedium without breaking the vacuum, cleaning it to removeall-foreign matter, and returning the cleaned sealing medium withoutdisturb ing the vacuum in the vacuum chamber.

13. In a vacuum apparatus the combination of a vacuum chamber, a liquidsealing said liquid seal of foreign matter without breaking the vacuumin the vacuum chamber. Y

14. In a vacuum apparatus the combina-- tion of a vacuum chamber, aliquid-sealing chamber,' "a weir or dam, a liquid seal a portion; ofwhich "is adapted to. flow over; the weir .or dam, and means to treat.said overflowing liquid to remove foreign matter,

and return the cleaned liquid to the sealing chamber. 7 Y 1 15. Inavac'uum apparatus the combina-'- tion of a vacuum'chamber, a' liquidsealing chamber, a'weir 'or dam, a well connected to. a cleaningchamber, acleaning chamber,

a liquid sealing medium, and means to force.

- .difi'erent'portion's of said liquid sealing me- -'tion of a vacuumchamber, a liquid sealing dium through the cleaning chamber to removeforeign matter from said liquid, and return the cleaned sealing liquidto the sea-l ing chamber. r p

16. In a vacuumapparatus the combinachamber, a weir or dam, a liquidseal of mercury or similar material, a portion of which is adapted toflow over the weir" or dam, andmeans to treat said overflowing mercuryorsimilar material to remove foreign matter, and return the cleanedmercury or similar material to the sealing chamber.

17. In a vacuum, apparatus the combina- 'to a cleaning chamber, acleaning chamber,

a strainer mounted in the cleaning chamber, mercury or similar materialmounted in the sealing chamber to seal the vacuum chamber there being alittle more mercury or similar material than necessary to fill thesealing chamber, and a pump to force the mercury or similar materialthrough the strainer in thecleaning chamber, and feed the cleanedmercury or similar material back to the sealing chamber. i

19. The method of drying sheet material and keeping it clean consistingin passing it through a liquid seal of a vacuum chamber, treating thesheet material in the Vacuum chamber, and removing a portion of saidliquid'seal without breaking the vacuum maintained by the sealorstopping the passage of the sheet material into and out of the vacuumchamber, cleaning said re moved portion of the liquid seal, and re-'turning the cleaned liquid to the seal so that the sheet material willbe kept clean asit passes through the seal.

20. The method ofdrying a web of paper and keeping it clean consistingin passing it through a liquid seal of a vacuum chamber, treating theweb of paper in the vacuum chamber, and removing .a portion of saidliquid seal without breaking the vacuum maintained by the seal orstopping the passage of the web of paper into out of the vacuum chamber,cleaning said removed portion of the liquid seal, and returning thecleaned liquid to the seal so thatthe web of. paper will be kept cleanas it passes through theseal.

21-. The method of vdryingsheet material and keeping it clean consistingin passing it through a liquid seal 'of a vacuum chamber, treating thesheet material in the vac% uum chamber, and automatically removingaportion of said liquid seal without'break-' the liquid seal, andautomatically returning the cleaned liquid to the seal so that the sheetmaterial will be kept clean as 1; passes is).

through the seal.

liquid to the seal so that the webof paper will be kept clean as itpasses through the sea 23. The method of drying a wet web of paper andkeeping the web clean consisting in passing the web through a mercuryseal or similar material sealing the entrance and exit passages of avacuum chamber, drying the wet web in the vacuum chamber, withdrawing itthrough a mercury seal, and removing a portion of said mercury orsimilar material without breaking the vacuum maintained by the seal orstopping the passage oi the Web into and out of the vacuum chamber,cleaning said removed portion of the seal and returning the cleanedmercury or similar material to the seal, so that the web will be keptclean as it passes through the seal.

24. The method of treating sheet material and keeping it cleanconsisting in passing it through a liquid eal of a vacuum chamber,treating the sheet material in the vacuum chamber, circulating an excessquantity of liquid through the liquid seal, and withdrawingthe excessliquid containing the impurities, cleaning said excess liquid, andreturning it to the liquid seals.

25. The method of treating a web of wet paper and keeping it cleanconsisting in passing it through. a liquid seal of a vacuum chamber,drying the web of paper in the vacuum chamber, circulating an'excessquantity of liquid through the liquid seal, and withdrawing the excessliquid containing the impurities, cleaning said excess liquid, andreturning it to the liquid seals. 26. The method of treating a web ofwet paper and keeping it clean consisting in passing it through a liquidseal of a vacuum chamber, drying the web in the vacuum chamber,permitting an excess quantity of the liquid of the liquid seal to flowwith it impurities into a well, withdrawing the excess liquid andimpurities from the well, cleaning it, and then returning the cleanedliquid free of-the impurities to' the liquid seal.

27. The method of treating a web of wet paper and keeping 'itcleanconsisting in passing it through a' circulating liquid of a liquid sealof a vacuum chamber, drying the 1 web in the vacuum chamber, permittingan excess quantity of the circulating liquid of the liquid seal to flowwith its impurities into a well, withdrawing the excessliquid andimpurities from the well, cleaning it, and then returning the cleanedcirculating liquid freeof the impurities to the liquid seal. I

OGDEN MINTON.

